Cold starting device of a rotary piston internal combustion engine

ABSTRACT

A cold starting device of a rotary piston internal combustion engine has a liquid feed tube holding an antifreeze liquid such as ethylene glycol and opening into an air intake duct or combustion chamber, and a solenoid controlled pump connected to the liquid feed tube for feeding antifreeze liquid, responsive to operation of the starter motor.

United States Patent Mukai et a1.

COLD STARTING DEVICE OF A ROTARY PISTON INTERNAL COMBUSTION ENGINE Inventors: Seiki Mukai; I-Iironori Koge, both of Hiroshima, Japan Assignee: Toyo Kogyo Co., Ltd., Japan Filed: Dec. 3, 1973 Appl. No.: 420,837

Related US. Application Data Continuation-impart of Ser. No. 240,023, March 31,

1972, abandoned.

[30] Foreign Application Priority Data Mar. 31, 1971 Japan 46-23955[U] [52] US. Cl. l23/8.l3; 123/179 B [51] Int. Cl. F02B 53/00; FO2N 17/08 [58] Field of Search 123/801, 8.13, 179 R, 123/179 B, 179 BG, 179 L, 187.5 R, 196 S, 196 M, 198 A, l A; 184/63 [56] References Cited UNITED STATES PATENTS 2,001,164 5/1935 Swan et a1. 123/127 1451 Sept. 30, 1975 2,518,712 8/1950 Ovens 123/1875 R 2,592,945 4/1952 Odell 123/1875 R 3,300,124 l/1967 Jones 123/845 X 3,704,702 12/1972 A0110 123/1875 R X 3,827,417 8/1974 Morita 123/1875 R X Primary E.\'amiI1erC. .1. Husar Assistant Examiner-Michael Koczo, Jr. Attorney, Agent, or FirmSughrue, Rothwell, Mion, Zinn & Macpeak 5 7 ABSTRACT A cold starting device of a rotary piston internal combustion engine has a liquid feed tube holding an antifreeze liquid such as ethylene glycol and opening into an air intake duct or combustion chamber, and a solenoid controlled pump connected to the liquid feed tube for feeding antifreeze liquid, responsive to operation of the starter motor.

2 Claims, 1 Drawing Figure U.S. Patent Sept. 30,1975

COLD STARTING DEVICE OF A ROTARY PISTON INTERNAL COMBUSTION ENGINE This application is a continuation in part application of copending application Ser. No. 240,023filed on March 31, 1972, for A Cold Starting Device of a Rotary Piston Internal Combustion Engine", and now abandoned.

BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION This invention relates to a cold starting device for a rotary piston engine. and more particularly to a device for supplying an antifreeze liquid to the combustion chamber of an engine during cranking so as to improve the starting performance in winter.

2. DESCRIPTION OF THE PRIOR ART Heretofore, when the internal combustion engine is started in winter, the cranking speed of the engine is lowered due to the insufficient torque of the starter motor due to the lower performance of the battery and insufficient lubricating oil in the combustion chamber. Particularly when the rotary piston engine is started in winter, insufficient compression pressure of the combustion chamber takes place, in addition to reduction of the cranking speed of the engine, and accordingly it is very difficult to start. More particularly, since the intake air is also at a very low temperature and insufficient compression pressure takes place due to the de crease of the cranking speed of the engine and leakage of compression, the temperature of the compressed mixture gas is not increased and improper ignition takes place. For this reason, even if the compressed mixture gas is ignited, its explosion force does not increase the engine speed, nor rotate the engine automatically by itself, and it sometimes becomes impossible to start the engine.

When the internal combustion engine is cold, the moisture in the air-fuel mixture or exhaust gas is frozen so that it frequently adheres to the inner wall surface of the cylinder and accordingly the inner wall surface of the casing forming the working chamber of a rotary piston engine. When such ice adheres to the inner wall of the casing of a rotary piston engine, leakage of compressed gas is remarkable so that the compression pressure of the working chamber does not increase with the result that starting of the rotary piston engine is almost impossible to achieve. For example, in a rotary piston engine, the compression pressure of the working chamber is maintained by the apex seals of the rotary piston sealingly sliding on the inner wall surface of the casing. However, ice adheres to the inner wall surface of the casing of the rotary piston engine in a not uniform mannen, and the surface of the ice is not smooth, and accordingly the compression gas tends to leak between the inner wall surface of the casing and the apex seal with the result that the starting of the rotary piston engine cannot be obtained.

Since the moisture component generated by the instantaneous combustion of initial internal explosion is also frozen when the rotary piston engine is started in cold state and it adheres to the inner wall surface of the casing of the rotary piston engine, leakage of the compressed gas occurs and improper ignition takes place with the result that the starting of the rotary piston engine becomes, at best, very difficult.

Since the sliding portions of the apex seals of the rotary piston on the inner wall surface of the casing are smooth, the ice adhered onto the inner wall surface of the casing is not scratched off by the moving apex seals of the rotary piston. and accordingly the starting of the rotary piston engine is particularly difficult when in the cold state.

In order to enable the rotary piston engine to start in cold state, it is proposed to introduce oil into the working chamber when the rotary piston engine is started. The rotary piston engine can be started in cold state by introducing oil into the working chamber of the rotary piston engine when it is not too cold, but it is almost impossible to start the rotary piston engine when in a severe cold state even if oil is introduced into the working chamber of the rotary piston engine. Since ice adheres to the inner wall surface of the casing under such conditions, compressed gas leaks between the inner wall surface of the casing and the apex seals. and if oil is introduced into the working chamber of the rotary piston engine, oil covers the ice, that is, oil exists between the ice and apex seals so as to prevent the compressed gas from leaking. Therefore, if oil effectively spans the freezing moisture and the apex seals, the starting of the rotary piston engine becomes possible. However, when the engine is in the severe cold state, the state and quantity of the freezing moisture adhered onto the inner wall surface of the working chamber is worse, and even if oil exists between the freezing moisture and the apex seals, starting of the rotary piston engine is impos- Sible.

The present invention contemplates to eliminate the aforementioned disadvantages of the conventional rotary piston engine. I

It is, therefore, an object of the present invention to provide a cold starting device for a rotary piston engine which enables starting of a rotary piston engine which was impossible heretofore to start in winter.

It is another object of the present invention to provide a rotary piston engine which has a device for supplying antifreeze liquid to its combustion chamber during cranking.

It is still another object of the present invention to provide a cold starting device for a rotary piston internal combustion engine which prevents the moisture from adhering to the inner wallsurface of the casing of the rotary piston engine from icing and introduces an antifreeze liquid or deicing liquid which functions to dissolve the freezing moisture on the inner wall surface of the casing by introducing the liquid into the intake duct or into the working chamber of the rotary piston engine.

SUMMARY OF THE INVENTION According to the present invention, the features of the cold starting device includes: a solenoid controlled pump for feeding antifreeze liquid in cooperation with a starter motor to supply the antifreeze starting liquid through an air intake duct or directly to the combustion chamber when the rotary piston engine is started, lessening the leakage of compression so as to provide proper intake air and fuel in order to improve the starting nature of the engine.

According to one aspect of the present invention, there is provided a cold starting device for a rotary piston engine which comprises a liquid feed tube for antifreeze liquid opening at the air intake duct or combustion chamber, and a solenoid pump connected to the liquid feed tube for feeding liquid and operating with BRIEF DESCRIPTION OF THE DRAWING The FIGURE is a partial schematicppartial sectional view of one embodiment of the cold starting device of a rotary piston engine according to this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT A rotary piston engine 1 includes a casing having the inner peripheral surface 2 of epitrochoidal curve and a rotor 3 rotating eccentrically in contact with the inner peripheral surface 2 thereof. When this rotor 3 is rotated, themixture gas is taken in, from an air intake 7 duct 6, through an air intake port 7, into a combustion chamber 8. The mixture ratio and amount of the mixture gas are controlled by the opening of the throttle valve 4 of a carburetor 5. This mixture gas is compressed as the rotor 3 rotates, and ignited by the ignition plugs 9 and 10 near top dead center to be exploded so as to expand while imparting a rotary force to the rotor 3 and then to be exhausted from the exhaust port 11'. At rotor 3 are apex seal 12 and side seals 13 in order to improve the airtightness between the rotor 3 and the inner peripheral surface 2 or the side housing. In the event that movable contact 15 of an ignition switch 14 contacts stationary contact 16, the electric power of the battery 17 is supplied to the ignition coils l8 and 19 so that the ignition plugs 9 and 10 ignite in accordance with the operation of'the interrupters 20 and 21. A starter motor 22 for rotating the rotor 3 at the start of the engine'is energized by a battery 17 so as to drive the rotor 3 when the movable contact 15 of the ignition switch 14 contacts the stationary contact 23. Air intake tube 6 is connected through a tube 25, manual cock 26, tube 27, pump 28 and a tube 29 to a tank 24 holding an antifreeze liquid such as an antifreeze solution; a deicing solution, or a' starting liquid having the antifreezing property. Alternatively, tube 29 may lead directly into the combustion chamber 8 as shown in dotted lines at 29a, opening at 29b. The starting liquid may comprise ethylene glycol. More particularly. such a liquid has the property of dissolving ice or freezing moisture adhered to the inner peripheral surface 2 of the casing and also preventing the moisture from adhering onto the inner peripheral surface 2 of the casing and is used as antifreeze liquid of the cold starting device of the present invention. The solenoid motor 30 of the pump 28 is connected through a relay switch 31 to a stationary contact 23. The solenoid 34 of the relay switch 31 is energized in winter by a transistor 33 made conductive by a thermosensor 32 changing the resistance by the change of the temperature of the cooling liquid.

In operation of thus constructed cold starting device of the rotary piston internal combustion engine. when the engine is started in the cold state by connecting the vmovable contact 15 of the ignition switch 14 to the stationary contacts 16 and 23,. the resistance of the thermosensor 32 is large because the rotary piston internal combustion engine 1 is at low temperature, and accordingly the thermosensor 32 causes the transistor 33 to conduct so as to energize the solenoid 34, and therefore the contact of the relay switch 31 is closed. Therefore. in this case, the ignition plugs 9 and 10 are in the operable'state as is therotary starter motor 22 in order to rotate the rotor 33 at the same time the pump 28 is driven by the solenoid motor 30 so as to feed the antifreeze liquid from the tank 24 into the air intake duct 6. Therefore. the antifreeze liquid is taken into the combustion chamber 8 together with the mixture gas from the carburetor 5 with the result that the sealing effectof the apex seal 12 and the side seal 13 is increased by this antifreeze liquid. Particularly, this antifreeze liquid has a great deal of anti-freezing effect so as to prevent the moisture from freezing on the inner wall of the working chamber and to melt any freezing moisture or ice on the inner wall of the working chamber, and accordingly it is optimum as a starting liquid for the cold starting device of this invention. For this reason, when the rotor 3rotates by the rotation of the starter motor 22, gas may not leak from the combustion chamber 8 during compression stroke, and accordingly the compression pressure sufficiently increases so that the intake mixture gas is at high temperature and high pressure at the igniteposition defined by the ignition plugs 9 and 10, and accordingly it reaches the state of beingextremely ignitable. Therefore, when this intake v-mixture gas is ignited by the ignition plugs 9 and 10, it

explodes so that the rotor 3 may rotate by itself with the result that the engine speed increases from the crankingv speed by the starter motor 22 to the idling speed so as to sufficiently continue to rotate.

When the starting of the engine is thus completed,

. the movable contact 15 of the switch 14 separates from thestationary contact 23 so as to stop the rotation of the starter motor 22 and the solenoid motor 30 of the pump 28.

In cold starting at normal atmospheric temperature and starting after warming-up operation in winter, the resistance of the thermosensor 32'becomes very small and the transistor 33 become non-conductive with the result that the relay switch 31 opens, and when the movable contact 15 of the switch 14 contacts the stationary contact 23, the solenoid motor 30 does not r0- tate, but only the starter motor 22 may rotate.

Though the antifreeze liquid supply port is provided at the air intake tube in the aforementioned embodiment, it may open directly to the combustion chamber.

Since the antifreezing liquid prevents the freezing moisture from being adhered onto the inner surface of the combustion chamber 8 and dissolve the freezing moisture on the inner surface of the casing, it is preferably introduced into the working chamber in the flowing, liquid state. The antifreeze liquid within tank 24 is not a primer. that is, it is not a fuel and as stated previously is not oil, but rather must have, as its primary characteristic the capacity to melt at lowtemperatures preformed ice as well as to prevent condensation from freezing on the combustion chambersurfaces of the casing. 7

While this invention is not limited to the aforementioned embodiment, but other means may be adopted if the starting liquid is supplied to the combustion chamber during cranking of the engine.

It should be understood from the foregoing description that since thecold'starting device of a rotary piston engine of this invention may supply antifreeze liquid into the combustion chamber during cranking to increase the sealing effect so as to reduce the leakage of the compression when the rotary piston engine starts in winter. it may improve the starting nature and reduce the wear of the sliding surfaces of the operating chambers at starting of the engine.

What is claimed is:

l. A cold starting device for a rotary piston internal combustion engine, said engine comprising: a casing having a trochoidal inner peripheral surface. and a rotor disposed in the casing for planetary rotation and having apex seals in sliding contact with the trochoidal inner peripheral surface so as to define working chambers between the casing and the rotor, the improvement comprising:

a. a battery;

b. a starter motor for cranking the engine during engine starting by motor energization;

c. a starter switch operatively connected to said battery and said starter motor for energizing the starter motor when the starter switch is closed;

d. a supply of antifreeze liquid;

e. a liquid feed tube;

f. an intake duct leading to one of said chambers which acts as an engine combustion chamber, said liquid feed tube coupling said antifreeze liquid supply to said intake duct;

g. pump means connected to the liquid feed tube for supplying the antifreeze liquid to the combustion chamber of the engine through said intake duct during pump operation to prevent moisture from freezing on the trochoidal inner peripheral surface and to dissolve ice formed thereon;

h. means electrically connecting said pump means to the starter switch such that the pump means operates at the same time that the starter motor is energized;

. a thermosensor for detecting engine temperature;

and

j. means operatively electrically connecting said thermosensor to said pump means such that when the temperature detected by the thermosensor reaches a predetermined temperature. said pump means is disconnected from said battery.

2. A cold starting device for a rotary piston internal 5 combustion engine, said engine comprising: a casing having a trochoidal inner peripheral surface. and a rotor disposed in the casing for planetary rotation and having apex seals in sliding contact with the trochoidal inner peripheral surface so as to define working cham- 10 bers between the casing and the rotor. the improvemerit comprising:

a. a battery;

b. a starter motor for cranking the engine during engine starting by motor energization;

c. a starter switch operatively connected to said battery and said starter motor for energizing the starter motor when the starter switch is closed;

d. a supply of antifreeze liquid;

e. a liquid feed tube connecting said antifreeze liquid supply to one of said chambers of said engine which acts as the combustion chamber;

e. an intake duct leading to one of said chambers;

f. pump means connected to the liquid feed tube for supplying the antifreeze liquid to the combustion chamber of the engine through said intake duct during pump operation to prevent moisture from freezing on the trochoidal inner peripheral surface and to dissolve ice formed thereon;

g. means electrically connecting said pump means to the starter switch such that the pump means operates at the same time that the starter motor is energized;

h. a thermosensor for detecting engine temperature;

and

i. means operatively electrically connecting said thermosensor to said pump means such that when the temperature detected by the thermosensor reaches a predetermined temperature, said pump means is disconnected from said battery. 

1. A cold starting device for a rotary piston internal combustion engine, said engine comprising: a casing having a trochoidal inner peripheral surface, and a rotor disposed in the casing for planetary rotation and having apex seals in sliding contact with the trochoidal inner peripheral surface so as to define working chambers between the casing and the rotor, the improvement comprising: a. a battery; b. a starter motor for cranking the engine during engine starting by motor energization; c. a starter switch operatively connected to said battery and said starter motor for energizing the starter motor when the starter switch is closed; d. a supply of antifreeze liquid; e. a liquid feed tube; f. an intake duct leading to one of said chambers which acts as an engine combustion chamber, said liquid feed tube coupling said antifreeze liquid supply to said intake duct; g. pump means connected to the liquid feed tube for supplying the antifreeze liquid to the combustion chamber of the engine through said intake duct durinG pump operation to prevent moisture from freezing on the trochoidal inner peripheral surface and to dissolve ice formed thereon; h. means electrically connecting said pump means to the starter switch such that the pump means operates at the same time that the starter motor is energized; i. a thermosensor for detecting engine temperature; and j. means operatively electrically connecting said thermosensor to said pump means such that when the temperature detected by the thermosensor reaches a predetermined temperature, said pump means is disconnected from said battery.
 2. A cold starting device for a rotary piston internal combustion engine, said engine comprising: a casing having a trochoidal inner peripheral surface, and a rotor disposed in the casing for planetary rotation and having apex seals in sliding contact with the trochoidal inner peripheral surface so as to define working chambers between the casing and the rotor, the improvement comprising: a. a battery; b. a starter motor for cranking the engine during engine starting by motor energization; c. a starter switch operatively connected to said battery and said starter motor for energizing the starter motor when the starter switch is closed; d. a supply of antifreeze liquid; e. a liquid feed tube connecting said antifreeze liquid supply to one of said chambers of said engine which acts as the combustion chamber; e. an intake duct leading to one of said chambers; f. pump means connected to the liquid feed tube for supplying the antifreeze liquid to the combustion chamber of the engine through said intake duct during pump operation to prevent moisture from freezing on the trochoidal inner peripheral surface and to dissolve ice formed thereon; g. means electrically connecting said pump means to the starter switch such that the pump means operates at the same time that the starter motor is energized; h. a thermosensor for detecting engine temperature; and i. means operatively electrically connecting said thermosensor to said pump means such that when the temperature detected by the thermosensor reaches a predetermined temperature, said pump means is disconnected from said battery. 